Electric switch



Dec. 14, 1948. s. s. GRADY 2,455,927

ELECTRIC SWITCH Filed July 2l, 1945 lNvEN-ron l By,

ATTORNEY Patented Dec. 14, 1948 UNITED STATES PATENT OFFICE ELECTRICSWITCH Stephen S. Grady, New York, N. Y.

Application July 21, 1945, Serial No. 606,369

6 Claims. l

This invention relates to electric switches in general and moreespecially to toggle switches.

Among the objects ci the present invention, it isaimed to provide animproved electric switch of the toggle or snap switch type in which themain contacts may be disengaged without interrupting the current andthereby in turn practically eliminate the arc formation, and confine thearc formation, if any, to a quick breaking narrow area.

It is still another object of the present invention to provide animproved electric switch of the toggle or snap switch type having mainkand auxiliary contacts, the auxiliary contacts being engaged nrst incircuit making action and disengaged last in circuit interrupting actionto eliminate arc formation between the main contacts either during themaking or breaking of the circuit.

It is still another object of the present invention to provide animproved electric switchhaving main contacts which engage face to face,one of which main contacts is yieldable to cause the contacting faces tomove relative to one another while in engagement with one another duringmaking and breaking of a circuit in turn to clean the surfaces of anyaccumulation of dirt or foreign material.

These and other features, capabilities and advantages of the inventionwill appear from the subjoined detail description of one specificembodiment thereof illustrated in the accompanying drawings in whichFig. 1 is a front elevation of the switch in closed position;

Fig. 2 is a rear elevation of the switch in closed position;

Fig. 3 is a section on the line 3 3 of Fig. 1;

Fig. 4 is a section on the line 4-4 of Fig. 1;

Fig. 5 is a rear elevation of the switch with the handle partly movedinto a position before breaking the contact.

In the embodiment shown, there is provided a casing having a base i towhich are connected two side walls 2 and 3, On the base there aremounted two brackets 4 and 5 connected to the terminals (not shown) ofthe switch. The contact bracket .4 has the fiange 6 with an openingtherein to receive a screw or the like to connect the flange 6 to thebase l and the bearing bracket 5 in thev present instance has a ange 1provided with a recess 8 to receive a screw or the like to connect theflange 'l to the base l. The brackets 4 and 5 are in turn insulated fromone anotherby, and connected to the insulation block 9. The bracket ilhas a connecting portion lil, double thickness in the present instance,connected ,to the block 9 by screws such as the screw ii, and thebracket 5 in turn has a flange i2 connected to the block Si by screwsauch as the screw I3. The bracket l in the present instance constitutesthe first Contact of the switch andy is provided with two contactingsections, to Wit, the narrow section i4 and the wide section or plate l5connected to one another by the connecting portion it. The wide sectioni5, in the present instance, is separated from the connecting portion lby the slot i6, which extends down to the point Il, see Fig. l, in orderthat the section I is free to yield when engaged by the fdange i8constituting one of the movable contacts ci the switch. When so yieldingupon initial con tact, a wiping or rubbing action will take placebetween the engaging faces of the plates i5 and i8 to free the engagingsurfaces from any carbon that might collect as a result of arcing duringmaking or breaking of the circuit.

The movable contact i8 in the present instance isformed on the blade i9pivotally connected by the pin to the flange 2l on the bracket 5. Theblade IS has an opening 22 therein, the ends of which cooperate with thepin or projection 23 on the arm 24 pivotally connected at 25 to theflange 2B formed on the bracket 5. The bar 24 extends downwardly fromthe flange 2t and the lower edge thereof in the contact making positionshown in Figs. 1 and 2 engages the narrow fixed contact area Hl of thebracket 4. The blade i9 and the 2t cooperate with the pivot pinsk 2D and25 and the spring 2l to constitute a toggle leverage which will belocked in place to either side of the pivot pin 25 by the spring 21 inthe usual way, the one end of the spring being connected to theprojection 2li in the pren sent instance alining with the pinI 2?, andthe other end of the'spring being connected to the projection 29 formedon the blade i9 on the other side of the pivot point 25.

Preferably for manipulating theblade i9, it is provided with a handlecomposed of insulating material which has the arcuate shield extensions3| and 32 preferably integral with the handle 30 and also composed ofinsulating material. The shield portions 3i and 32 thus serve in a wayto protect the fingers of the user from any short circuit or arc thatmight be created during the making or breaking of the circuit in the actof opening or closing the circuit,

The-pin 25 extends through the upper portion of the insulating block 9from the ange 26 to 3 the contact disk 33 which is in wiping contactwith the blade I9.

The block 9 is provided with a slot 34 to form a clearance for the pin23, and, see Fig. 4, is also provided with a slot 35 to form a clearancefor the lower end of the arm 24 by eifectively insulating the lower endof the arm 24 from the bracket 4 when the switch is in open position.Preferably as shown, the insulating block may be composed of two parts,the part 36 and the angle strip 31 having the web 38 secured to thebottom of the part 36 and the web 39 spaced from the bottom of the part36 to form a clearance between the web 39 and the part 36 for the lowerend of the arm 24.

The lower portion 40 of the insulation part 36, as is clearly shown inFig. 4, separates the arm 24 from the blade I9 so that, see Fig. 3,after the switch has been closed, both the flange I8 engages the plateI5, and the blade 24 engages the portion I4 of the bracket 5. Then uponstarting to open the switch, see Fig. 5, the blade I9 will rst cause theflange I8 to clear the plate I5 when the current will continue to llowfrom one terminal to the other through the arm 24 and contact portion I4of the bracket 5 and the switch will not be opened until the blade I9has moved the abutment 29 of the spring 21 so that the spring 21 willpass to the other side of the dead center or pivot pin 25 to cause thearm 24 quickly to snap out of contact with the portion I4 and move overinto the open position where the pin 23 approaches the other end of therecess 22, namely the end 4I, when the lower end of the arm 24 willengage the inner face of the bracket 4.

When again actuating the blade I9 to close the switch, the end 4I of therecess 22 will first move into engagement with the pin 23 and afterengaging the same cooperate with the spring 21 to swing the lower end ofthe arm 24 into engagement with the contact portion I4 of the bracket 4,the spring 21 of course entering into play as soon as it passes the deadcenter or pivot pin 25 in the well known action of a toggle. In thefinal position of the blade I9, see Fig. 2, the spring 21 will alsooperate or function to cause the flange I to engage the plate I5.

In operation it will thus be seen that when the switch is closed, thecurrent will pass from a terminal of the conductor, not shown, connectedto the bracket 4 either through the plate I8 to the flange I5 of theblade I9, then from the blade I9 through the bracket 5 to the otherterminal or else when the blade I9 has caused the flange I8 to be spacedfrom the plate I5 then the current will pass from the bracket 4 throughthe contact portion I4 to the arm 24 and then from the arm 24 pivotallyconnected to the bracket 5 through the bracket 5 to the other terminalof the conductor. In this way, when the blade I 9 is in its closedposition as shown in Fig. 2, the extended area of the flange I5 willcooperate with the blade I8.

From the foregoing it will thus appear that the initial make and breakof the circuit will be effected by the edge of the arm 24 engaging theportion I4 of the bracket 4, a comparatively narrow surface, :and themake and break with the edge of the arm 24 will be an exceedingly fastone so that if an overload did occur, before it could cause any harm tothe switch, in the opening of the switch, the spring 21 would come intoplay to cause the switch to open immediately, and in turn, when closingthe switch, also while the arm 24 may be the first to establish acurrent through the :area I4 of the bracket 4, the successive contactbetween the flange I8 and plate I5 will follow so quickly after initialcontact is made that no harm can come to the switch, and on the otherhand, when the extended face of the flange I8 engages the plate I5, thena sulliciently large Iarea will be in contact to reduce the resistanceand effectively take care of an ordinary overload without injury to theswitch- In turn, upon opening of the switch, due to the fact that thearm 24 will still be in contact with the portion I4 of the bracket 4when an extended surface of the flange I8 recedes from the plate I5, seeFig. 5, no arc will take place during this opening movement.Furthermore, if any dirt or foreign material should have collected onthe faces of the flange I8 and plate I5, such dirt or foreign materialwill be wiped off or rubbed off, due to the yieldability of the plate I5and relative movement of the plate I5 and flange I8 as :a result of thisflexibility while the ilange I8 is making contact with the plate I5 orleaving the plate I5. In other Words, when the flange I8 initiallyengages the plate I5, before the two come to rest, there will be asurface movement of one relative to the other due to the yieldability ofthe plate I5 which surface movement will again occur when the blade I9is started on its movement to open position.

It is obvious that various changes and modiiications may be made to thedetails of construction without departing from the general spirit of theinvention as set forth in the appended claims.

I claim:

1. The combination of a bearing bracket con stituting one terminal of anelectric circuit, a blade and an arm pivotally connected at spaced apartportions of said bearing bracket, a spring connected at one end to saidarm and at its other end to said blade, a contact bracket constitutingthe other terminal of an electric circuit, the spring being positionedto one side of 'the pivotal connection of said arm when said blade andarm are spaced from said contact bracket, said contact bracket having aflexible contact plate, and a contact flange on said blade, the springbeing positioned to one side of the pivotal connection of said arm whensaid arm and blade are maintained in open switch position and saidspring being positioned to the other side of the pivotal connection ofsaid arm when said spring yieldably maintains the free end of said armin contact with said contact bracket and the flange of said blade incontact with said flexible plate, said blade being movable relative tosaid arm so that said flange may be withdrawn out of contact with saidflexible plate before the free end of said arm is withdrawn from contactwith said contact bracket.

2. The combination of a bearing bracket con- Stitutllg one terminal ofan electric circuit, a blade and an arm pivotally connected to saidbracket. a spring connected at one end to said arm and at its other endto said blade, a contact bracket constituting the other terminal of anelectric circuit, the spring being positioned to one side of the pivotalconnection of said arm when said blade and arm are spaced from saidcontact bracket, said contact bracket having a flexible contact plate, acontact flange on said blade, the spring being positioned to one side ofthe pivotal connection of said arm when said arm and blade aremaintained in open switch position and said spring being positioned tothe other side of the pivotal connection of said arm when said springyieldably maintains the free end of said arm in contact with saidContact bracket and the flange of said blade in contact with saidflexible plate, said blade having an opening therein with abutments atthe ends thereof, and a projection on said arm extending into saidopening and cooperating with said abutments and said spring to snap saidarm and blade into open or closed position immediately that said springpasses the pivotal connection of said arm.

3. The combination of a bearing bracket constituting one terminal of anelectric circuit, a blade and an arm pivotally connected at spaced apartportions of said bearing bracket, a spring connected at one end to saidarm and at its other end to said blade, a contact bracket constitutingthe other terminal of an electric circuit, the spring being positionedto one side of the pivotal connection of said arm when said blade andarm are spaced from said contact bracket, said contact bracket having aflexible contact plate, a Contact flange on said blade, the spring beingpositioned to one side of the pivotal connection of said arm when saidarm and blade are maintained in open switch position and said springbeing positioned to the other side of the pivotal connection of said armwhen said spring yieldably maintains the free end of said arm in contactwith said contact bracket and the flange of said blade in contact withsaid flexible plate, and an insulated extension on said blade to serveas a handle for actuating the blade.

4. The combination of a bearing bracket having two flanges at itsopposite ends and constituting one terminal of an electric circuit, ablade pivotally connected to one of said flanges and extending to andbeyond the other flange, an arm pivotally connected to said other flangeand extending parallel to said one flange, a spring connected at one endto said arm below its pivotal connection with said other flange andconnected to said blade beyond said other flange, a contact bracketconstituting the other terminal of the electric circuit, a flexibleplate formed on said Contact bracket, and a flange formed on saidpivotal blade and contacting said flexible plate when the spring ispositioned to one side of the pivotal connection to close the circuitwhen the free end of said arm also contacts said contact bracket.

5. The combination of a bearing bracket having anges at its oppositeends and constituting one terminal of an electric circuit, a bladepivotally connected to one of said flanges and extending to and beyondthe other flange, an arm pivotally connected to said other flange andextending parallel to said one flange, a spring connected at one end tosaid arm below its pivotal connection with said other flange andconnected to said blade beyond said other flange, a contact bracketconstituting the other terminal of the electric circuit, a flexibleplate formed on said contact bracket, a flange formed on said pivotalblade and contacting said flexible plate when the spring is positionedto one side of the pivotal connection to close the circuit when the freeend of said arm also contacts said contact bracket, there being anopening in said pivotal blade having abutments at its opposite ends, anda projection on said arm cooperating with said abutments and said springto snap said arm and pivotal blade into and out of closed position.

6. The combination of a bearing bracket having flanges at its oppositeends and constituting one terminal of an electric circuit, a bladepivotally connected to one of said flanges and extending to and beyondthe other flange, an arm pivotally connected to said other flange andextending parallel to said one flange, a spring connected at one end tosaid arm below its pivotal connection with said other flange andconnected to said blade beyond said other flange, a contact bracketconstituting the other terminal of the electric circuit, a flexibleplate formed on said contact bracket, a flange formed on said pivotalblade and contacting said flexible plate when the spring is positionedto one side of the pivotal connection to close the circuit when the freeend of said arm also contacts said contact bracket, there being anopening in said pivotal `blade having abutments at its opposite ends,and

a projection on said arm cooperating with said abutinents and saidspring to snap said arm and pivotal blade into and out of closedposition, said pivotal blade being movable relative to said arm towithdraw said flange from said flexible plate before said arm iswithdrawn from said contact bracket in circuit interrupting operation,and said flexible plate and flange being movable relative to o-neanother when in contact with one another to remove any deposits of dirtor foreign material.

STEPHEN S. GRADY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,155,157 Lewis Sept. 28, 19151,383,695 Comboni July 5, 1921 1,407,603 Timmons Feb. 21, 1922 1,829,514Grossman et al. Oct. 27, 1931 2,308,026 Rawlins Jan. 12, 1943

